From: Romain Naour romain.naour@gmail.com
commit 1d7ba0165d8206ac073f7ac3b14fc0836b66eae7 upstream
From [1]
"GCC 10 (PR 91233) won't silently allow registers that are not architecturally available to be present in the clobber list anymore, resulting in build failure for mips*r6 targets in form of: ... .../sysdep.h:146:2: error: the register ‘lo’ cannot be clobbered in ‘asm’ for the current target 146 | __asm__ volatile ( \ | ^~~~~~~
This is because base R6 ISA doesn't define hi and lo registers w/o DSP extension. This patch provides the alternative clobber list for r6 targets that won't include those registers."
Since kernel 5.4 and mips support for generic vDSO [2], the kernel fail to build for mips r6 cpus with gcc 10 for the same reason as glibc.
[1] https://sourceware.org/git/?p=glibc.git%3Ba=commit%3Bh=020b2a97bb15f807c0482... [2] '24640f233b46 ("mips: Add support for generic vDSO")'
Signed-off-by: Romain Naour romain.naour@gmail.com Signed-off-by: Sudip Mukherjee sudipm.mukherjee@gmail.com Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de Signed-off-by: Sudip Mukherjee sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/mips/vdso/gettimeofday.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
--- a/arch/mips/vdso/gettimeofday.c +++ b/arch/mips/vdso/gettimeofday.c @@ -18,6 +18,12 @@ #include <asm/unistd.h> #include <asm/vdso.h>
+#if MIPS_ISA_REV < 6 +#define VDSO_SYSCALL_CLOBBERS "hi", "lo", +#else +#define VDSO_SYSCALL_CLOBBERS +#endif + #ifdef CONFIG_MIPS_CLOCK_VSYSCALL
static __always_inline long gettimeofday_fallback(struct timeval *_tv, @@ -34,7 +40,9 @@ static __always_inline long gettimeofday : "=r" (ret), "=r" (error) : "r" (tv), "r" (tz), "r" (nr) : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", - "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + "$14", "$15", "$24", "$25", + VDSO_SYSCALL_CLOBBERS + "memory");
return error ? -ret : ret; } @@ -55,7 +63,9 @@ static __always_inline long clock_gettim : "=r" (ret), "=r" (error) : "r" (clkid), "r" (ts), "r" (nr) : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", - "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + "$14", "$15", "$24", "$25", + VDSO_SYSCALL_CLOBBERS + "memory");
return error ? -ret : ret; }